Grade A Bolts | McMaster-Carr

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Unified Standard Class 2A

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Right Hand

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30,000 psi to 99,999 psi

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65 Products

Low-Strength ASTM Grade A Steel Square Head Screws


Fully Threaded	Partially Threaded

About half the strength of medium-strength screws, these screws can be used for light duty fastening applications, such as securing access panels. Large flat sides make them easy to grip with a wrench and keep them from rotating in square holes. Material meets ASTM A307 specifications for quality. Length is measured from under the head.

	Square Head Screws											Nuts
					Head
	Lg.	Threading	Min. Thread Lg.	Thread Spacing	Wd.	Ht.	Tensile Strength, psi	Specs. Met	Pkg. Qty.		Pkg.	Pkg. Qty.		Pkg.
Steel







				1/4"-20 Threads

				1"	Fully Threaded	—	Coarse	3/8"	11/64"	60,000	ASTM A307	25	91465A101	000000	100	94855A127	000000


				1 1/4"	Partially Threaded	3/4"	Coarse	3/8"	11/64"	60,000	ASTM A307	25	91465A104	00000	100	94855A127	00000
				1 1/2"	Partially Threaded	3/4"	Coarse	3/8"	11/64"	60,000	ASTM A307	50	91465A107	00000	100	94855A127	00000
				2"	Partially Threaded	3/4"	Coarse	3/8"	11/64"	60,000	ASTM A307	25	91465A110	00000	100	94855A127	00000




						5/16"-18 Threads

						3/4"	Fully Threaded	—	Coarse	1/2"	13/64"	60,000	ASTM A307	25	91465A113	00000	100	90043A030	00000


						1"	Fully Threaded	—	Coarse	1/2"	13/64"	60,000	ASTM A307	25	91465A116	00000	100	90043A030	00000
						1 1/4"	Fully Threaded	—	Coarse	1/2"	13/64"	60,000	ASTM A307	25	91465A119	00000	100	90043A030	00000
						1 1/2"	Partially Threaded	7/8"	Coarse	1/2"	13/64"	60,000	ASTM A307	10	91465A122	0000	100	90043A030	00000
						2"	Partially Threaded	7/8"	Coarse	1/2"	13/64"	60,000	ASTM A307	10	91465A125	00000	100	90043A030	00000
						3"	Partially Threaded	7/8"	Coarse	1/2"	13/64"	60,000	ASTM A307	10	91465A128	00000	100	90043A030	00000
						4"	Partially Threaded	7/8"	Coarse	1/2"	13/64"	60,000	ASTM A307	10	91465A131	00000	100	90043A030	00000




								3/8"-16 Threads

								1"	Fully Threaded	—	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A134	00000	100	90043A031	00000


								1 1/4"	Partially Threaded	1"	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A137	0000	100	90043A031	00000
								1 1/2"	Partially Threaded	1"	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A140	00000	100	90043A031	00000
								1 3/4"	Partially Threaded	1"	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A143	00000	100	90043A031	00000
								2"	Partially Threaded	1"	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A146	00000	100	90043A031	00000
								2 1/2"	Partially Threaded	1"	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A149	00000	100	90043A031	00000
								3"	Partially Threaded	1"	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A152	00000	100	90043A031	00000
								3 1/2"	Partially Threaded	1"	Coarse	9/16"	1/4"	60,000	ASTM A307	10	91465A155	00000	100	90043A031	00000




										1/2"-13 Threads

										1"	Fully Threaded	—	Coarse	3/4"	21/64"	60,000	ASTM A307	10	91465A158	00000	50	90043A055	00000


										1 1/2"	Fully Threaded	—	Coarse	3/4"	21/64"	60,000	ASTM A307	10	91465A161	00000	50	90043A055	00000
										1 3/4"	Fully Threaded	—	Coarse	3/4"	21/64"	60,000	ASTM A307	10	91465A164	00000	50	90043A055	00000
										2"	Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	10	91465A167	00000	50	90043A055	00000
										2 1/4"	Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	5	91465A170	00000	50	90043A055	00000
										2 1/2"	Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	5	91465A173	00000	50	90043A055	00000
										3"	Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	5	91465A176	00000	50	90043A055	00000
										3 1/2"	Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	5	91465A179	00000	50	90043A055	00000
										4"	Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	5	91465A182	00000	50	90043A055	00000
										5"	Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	5	91465A185	00000	50	90043A055	00000
6"										Partially Threaded	1 1/4"	Coarse	3/4"	21/64"	60,000	ASTM A307	5	91465A191	00000	50	90043A055	00000


8"	Partially Threaded									1 1/2"	Coarse	3/4"	21/64"	60,000	ASTM A307	1	91465A194	0000	50	90043A055	00000




		5/8"-11 Threads

		2"	Partially Threaded							1 1/2"	Coarse	15/16"	27/64"	60,000	ASTM A307	1	91465A209	0000	25	90043A065	00000


		2 1/2"	Partially Threaded							1 1/2"	Coarse	15/16"	27/64"	60,000	ASTM A307	5	91465A212	00000	25	90043A065	00000
		3"	Partially Threaded							1 1/2"	Coarse	15/16"	27/64"	60,000	ASTM A307	1	91465A215	0000	25	90043A065	00000
		3 1/2"	Partially Threaded							1 1/2"	Coarse	15/16"	27/64"	60,000	ASTM A307	1	91465A218	0000	25	90043A065	00000
		4"	Partially Threaded							1 1/2"	Coarse	15/16"	27/64"	60,000	ASTM A307	1	91465A221	0000	25	90043A065	00000
		4 1/2"	Partially Threaded							1 1/2"	Coarse	15/16"	27/64"	60,000	ASTM A307	1	91465A224	0000	25	90043A065	00000
		5"	Partially Threaded	1 1/2"						Coarse	15/16"	27/64"	60,000	ASTM A307	1	91465A227	0000	25	90043A065	00000
		6"	Partially Threaded	1 1/2"	Coarse					15/16"	27/64"	60,000	ASTM A307	1	91465A230	0000	25	90043A065	00000
		7"	Partially Threaded	1 3/4"	Coarse					15/16"	27/64"	60,000	ASTM A307	1	91465A233	0000	25	90043A065	00000
		11"	Partially Threaded	1 3/4"	Coarse					15/16"	27/64"	60,000	ASTM A307	1	91465A236	00000	25	90043A065	00000




				3/4"-10 Threads

				2 1/2"	Partially Threaded					1 3/4"	Coarse	1 1/8"	1/2"	60,000	ASTM A307	1	91465A242	0000	10	90043A075	00000


				3"	Partially Threaded					1 3/4"	Coarse	1 1/8"	1/2"	60,000	ASTM A307	1	91465A245	0000	10	90043A075	00000
				3 3/4"	Partially Threaded					1 3/4"	Coarse	1 1/8"	1/2"	60,000	ASTM A307	1	91465A248	0000	10	90043A075	00000
				4"	Partially Threaded					1 3/4"	Coarse	1 1/8"	1/2"	60,000	ASTM A307	1	91465A251	0000	10	90043A075	00000
				4 1/2"	Partially Threaded	1 3/4"				Coarse	1 1/8"	1/2"	60,000	ASTM A307	1	91465A254	0000	10	90043A075	00000
				5"	Partially Threaded	1 3/4"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A257	0000	10	90043A075	00000
				5 1/2"	Partially Threaded	1 3/4"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A260	0000	10	90043A075	00000
				6"	Partially Threaded	1 3/4"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A263	0000	10	90043A075	00000
				7"	Partially Threaded	2"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A266	0000	10	90043A075	00000
				8"	Partially Threaded	2"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A269	00000	10	90043A075	00000
				9"	Partially Threaded	2"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A272	00000	10	90043A075	00000


				10"	Partially Threaded	2"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A275	00000	10	90043A075	00000
				12"	Partially Threaded	2"	Coarse			1 1/8"	1/2"	60,000	ASTM A307	1	91465A278	00000	10	90043A075	00000




						1"-8 Threads

						6"	Partially Threaded	2 1/4"		Coarse	1 1/2"	21/32"	60,000	ASTM A307	1	91465A287	00000	5	90043A095	00000


						7"	Partially Threaded	2 1/2"	Coarse	1 1/2"	21/32"	60,000	ASTM A307	1	91465A290	00000	5	90043A095	00000
						9"	Partially Threaded	2 1/2"	Coarse	1 1/2"	21/32"	60,000	ASTM A307	1	91465A293	00000	5	90043A095	00000
						10"	Partially Threaded	2 1/2"	Coarse	1 1/2"	21/32"	60,000	ASTM A307	1	91465A296	00000	5	90043A095	00000